A color photographic material is exposed and then color-developed, whereupon an oxidized aromatic primary amine developing agent which is formed in the color developer during the color-development reacts with couplers in the material to give a color image. In the system of forming color images, color reproduction by a subtractive color process is employed, where yellow, magenta and cyan color images are formed for reproduction of blue, green and red, the former being complementary to the latter, respectively.
Couplers not only must form dyes, but also the dyes to be formed by the couplers should have an excellent spectral absorption characteristic, the dyes should have a high color density, the couplers should have a high dye-forming speed, and the dyes to be formed by them should have high fastness to light, heat and moisture. In particular, since photographic materials are desired to have high sensitivity and to provide a high-quality image, development of couplers having a high color image-forming rate and giving high-density color images is strongly desired.
In planning DIR couplers, which are couplers which release a development inhibitor when reacted with an oxidation product of an aromatic primary amine developing agent and which are used for the purpose of improving the sharpness and color reproducibility of photographic images, the above-mentioned properties are extremely important factors.
Regarding planning of coupler skeletons of yellow couplers for the purpose of elevating their color image-forming rate, British Patent 1,204,680, U.S. Pat. No. 4,149,886 and JP-A-57-151944 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") proposed a malondianilide skeleton and French Patent 991,453 and U.S. Pat. No. 2,500,487 proposed an alkoxyacetanilide skeleton. However, since all the proposed couplers have a poor color image fastness, they could not be put to practical use as a photographic color image-forming coupler. Since the alkoxyacetanilide couplers give a color image having a better color hue and a higher color image fastness than the malondianilide couplers, novel molecular planning of such alkoxyacetanilide couplers would be desirable so as to elevate them to a practical level.